Toner and method for producing toner

Abstract

A toner has a toner particle including a binder resin, the binder resin includes a polymer A, the polymer A contains a first monomer unit derived from a first polymerizable monomer and a second monomer unit derived from a second polymerizable monomer, the first polymerizable monomer is selected from (meth)acrylic acid esters having an alkyl group having 18 to 36 carbon atoms, the content of the first monomer unit in the polymer A is 5.0 mol % to 60.0 mol %, the content of the second monomer unit in the polymer A is 20.0 mol % to 95.0 mol %, the SP value of the first monomer unit and the SP value of the second monomer unit satisfy a predetermined relationship, the polymer A includes a predetermined polyvalent metal, and the content of the polyvalent metal is 25 ppm to 500 ppm.

Description

BACKGROUND OF THE INVENTIONField of the Invention[0001]The present invention relates to a toner suitable for an electrophotographic system, an electrostatic recording system, an electrostatic printing system and the like, and a method for producing the toner.Description of the Related Art[0002]As electrophotographic full-color copiers have become widespread in recent years, additional performance improvements such as higher speed and higher image quality and also energy saving performance and shortening of recovery time from the sleep state are required.[0003]Specifically, a toner that can be fixed at a lower temperature in order to reduce power consumption in a fixing process is needed to comply with energy saving requirements. Further, a toner excellent in charge retention property, which demonstrates small variation in charge quantity through a long sleep state, is needed as a toner capable of shortening the recovery time from the sleep state.[0004]Accordingly, in JP-A-2014-19942...

AI Technical Summary

Benefits of technology

[0007]As described in JP-A-2014-199423 and JP-A-2014-130243, the crystalline resin has a melting point and therefore exhibits excellent low-temperature fixability. Meanwhile, the crystalline resin has a low glass transition temperature, which is an index of molecular mobility, and therefore, development stripes are easily generated. Accordingly, it has been proposed to promote crystallinity of the binder resin by adding a crystal nucleating agent as described in JP-A-2012-247629, or to introduce an annealing step or the like, but the resulting effect on the suppression of development stripes is negligible.

[0010]It follows from the above, that the low-temperature fixability and the development stripes are in a trade-off relationship. Therefore, in order to overcome this trade-off relationship and to show excellent low-temperature fixability, it is urgently necessary to develop a toner that makes it possible to suppress development stripes even in long-term image output under a high-temperature and high-humidity environment and exhibits excellent charge retention property.

[0011]The present invention has been accomplished in view of the above problems. The present invention provides a toner that exhibits excellent low-temperature fixability and also makes it possible to suppress development stripes even in long-term image output under a high-temperature and high-humidity environment and exhibits excellent charge retention property. The present invention also provides a method for producing such toner.

[0051]According to the present invention, it is possible to provide a toner that exhibits excellent low-temperature fixability and also makes it possible to suppress development stripes even in long-term image output under a high-temperature and high-humidity environment and exhibits excellent charge retention property, and to provide a method for producing the toner.

Problems solved by technology

Then, such coarse particles may be caught between a developing sleeve and a regulating blade, and an image defect (development stripe) may occur because the portion where the coarse particles are caught is not developed.

However, for the same reason as related to the toner described in JP-A-2014-199423, an image defect (development stripe) may occur.

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